1. Field of the Invention
The present invention is directed to a device for cooling a blower motor used in a climate control system. More particularly, the invention is directed to a device for providing cooling air from an air conditioning plenum to the blower motor in the climate control system.
2. Disclosure Information
It is well-known that a stream of air from the passenger compartment of a motor vehicle may be drawn over a temperature sensor, to provide control of the temperature of air discharged into the passenger compartment by the vehicle's climate control system. This air typically is aspirated from the passenger compartment via a conduit connected either to the intake housing of the climate control system blower or to the suction housing of a separate small additional blower mounted behind the dashboard of the motor vehicle. U.S. Pat. No. 4,623,090 discloses a climate control system blower including a dual purpose fan, wherein air is aspirated from the passenger compartment of the motor vehicle by means of supplemental vanes attached to the backside of the impeller of the fan used to provide forced ventilation to the passenger compartment. This configuration, however, does not provide cooling for the blower motor. Without cooling, the motor could possibly become overheated, impairing its ability to function most efficiently.
U.S. Pat. No. 5,364,025, assigned to the assignee of the present invention discloses a combination motor cooler and air aspirator which could be integrated with the blower motor of a motor vehicle climate control system. Such a device provides a tubular coupling from the interior of the passenger compartment to the motor and eliminates the need for a separate small additional blower. This system also provides cooling to the climate control system blower motor.
Other proposals for providing cooling air to an air conditioning blower motor includes that described in U.S. Pat. No. 4,626,720. In the '720 patent, a coupling extends between the air conditioning duct housing and the blower motor. A vacuum is created by the blower to draw air through the coupling to the motor. The arrangement shown in FIG. 1 of the '720 patent illustrates that the coupling extends a small distance into the duct. Similar arrangements are shown in FIGS. 1A and 1B. In FIG. 1A, a tubular hose 12 extends through the plenum or duct sidewall 14 into an open area of the duct 16. Air flow is shown by arrows. In FIG. 1B, the hose 12 is flush with the sidewall 14. In both arrangements, very little air flows into the hose 12. This is because, in FIG. 1A, the air flow strikes the side of the hose 12 and creates a "dead zone" 18 or is forced over the hose, not into it. In FIG. 1B, the air flows over the top of the hose opening and because a vacuum is not created by the motor, the air is not drawn into the hose 12. Furthermore, the air flowing in FIG. 1B could create a venturi effect and draw air away from the motor, causing increased heating.
Therefore, there is a need for a device which maximizes the amount of air flowing from the air conditioning plenum and through a hose into the motor.